Fabric-tension mechanism for embroidering-machines.



H. ZAHN, DECD. A. RIETZSCH, ADMINISTRATOR. FABRIC TENSION MECHANISM FOR EMBROIDERING MACHINES. APPLICATION FILED FEB. 9, I914.

1,,18,1 Patented Aug. 3,1915.

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I I Iin' IIII OI I i:' I I I I I I wuewtoz MM qw'ablimmeq WW! M ROBERT ZAHN, DECEASED, IBY ALFRED RIETZSCH, ADMINISTRATOR, OF PLA'UEN, I

GERMANY.

Specification of Letters Patent.

Patented Aug. 3, 1915.

Application filed February 9, 1914. Serial No. 817,498.

" ZAHN did invent the new and useful Improvement in Fabric-Tension Mechanism for Embroidering-Machines, of which the annexed is a specification.

The longer and higher embroidering macinesare built, the more difiicult it becomes to stretch or tension suificiently taut the fabric surface which correspondingly increases in size. Hitherto the fabric has been stretched by directly imparting motion to the fabric roller through the medium of a coarsely notched disk which was turned by an iron bar. By reason of the coarseness of the notches of that disk and the direct transmission of movement to the fabric roller, a sufficiently fine adjustment of the fabric roller was impossible.

The object of the present invention is to provide means whereby the aforenamed drawback will be avoided.

My invention will be fully understood by reference to the accompanying drawing, in which similar reference characters denote corresponding parts and in which Figure 1 is an elevation of a part of the tambour frame and the fabric roller show ing my new mechanism for tensioning the fabric and Fig. 2 is a side elevation thereof.

Rotatively mounted in the tambour frame a are the toothedwheels b, b which are provided with square pivots 0 that engage central notches at provided in the heads 6 of the fabric roller f. At each end the fabric roller is centrally loosely borne on the axles of the wheels I). Meshing with each wheel I) is a smaller toothed wheel 9 fixed on a 1'0- tary spindle h which is arranged parallel to the axle of the wheel b and is also suitably borne in the tambour frame.

Fixed on the spindle h is a ratchet wheel 5 with which coiiperates a pawl j fulcrumed at t in a bracket is of the tambour frame. The ratchet wheel 1; is formed integrally with the usual coarsely notched disk i which is adapted to beturned as hitherto by an iron bar (not shown).

It will be obvious, that, notwithstanding the coarseness of the notches of the disk 6 the fabric'roller now could receive a fine adjustment to produce the desired tautness of the fabric, by reason of the interposition of the intermediate small gear, which at the same time permits a much greater force to be exerted on the fabric roller to stretch the fabric.

What I claim and desire to secure by Letters Patent is: 4

1. In an embroidering machine, the combination with a tambour frame and a fabric roller carried by the latter, of a tensioning device for the fabric, comprising a coarsely notched disk, a ratchet wheel connected to said disk, a pawl coiiperating with said wheel and transmission gears between said disk and the fabric roller, said notched disk serving for the engagement of a hand bar to impart movement thereto.

2. In an embroidering machine, the com bination with a tambour frame and a fabric roller carried by the latter, of a tensioning device for the fabric, comprising a coarsely notched disk, a ratchet wheel connected thereto, a pawl cooperating with said wheel, a small pinion connected to said disk and a larger pinion connected to said roller and meshing with the smaller pinion, the said notched disk serving for the engagement of a hand bar to impart movement thereto.

In testimony whereof I afiix my signature in presence of two witnesses.

' ALFRED RIETZSCH, Attorney, Plaucn, administrator of Robert Zaim, deceased.

Witnesses:

Josnr GRANZ, ROBERT H. Nam. 

